Vessel propulsion system and vessel having the same

Abstract

A vessel propulsion system includes two propulsion devices that are disposed on a left side and on a right side, respectively, with respect to a central line extending in a front-rear direction through a rotational center of a hull, an operating device that outputs a lateral movement command including a commanded direction, and a controller. The controller is configured and programmed to control the thrust and the steering angle of each of the two propulsion devices so that, when the operating device outputs a lateral movement command, a first propulsion device on a side existing in the commanded direction generates a backward thrust, whereas a second propulsion device generates a forward thrust, and so that an operating point of a resultant force of the thrusts of the two propulsion devices is positioned to deviate to the side in the commanded direction from the central line, and so that a direction of action of the resultant force follows the commanded direction.

What is claimed is: 
     
       1. A vessel propulsion system comprising:
 at least two propulsion devices that are disposed on a left side and on a right side, respectively, with respect to a central line extending in a front-rear direction through a rotational center of a hull and that are variable in thrust and in steering angle; 
 an operating device configured to output a lateral movement command to cause the hull to make a lateral movement in a lateral direction perpendicular to the central line, the lateral movement command including a commanded direction of either a rightward direction or a leftward direction in accordance with an operation performed by an operator; and 
 a controller configured and programmed to control the thrust and the steering angle of each of the two propulsion devices so that, when the operating device outputs the lateral movement command, a first one of the two propulsion devices that is disposed on a side existing in the commanded direction with respect to the central line generates a backward thrust, whereas a second one of the two propulsion devices that is disposed on a side existing in a direction opposite to the commanded direction with respect to the central line generates a forward thrust, and so that an operating point of a resultant force of the thrusts of the two propulsion devices is positioned to deviate to the side in the commanded direction from the central line, and so that a direction of action of the resultant force follows the commanded direction. 
 
     
     
       2. The vessel propulsion system according to  claim 1 , wherein the controller is configured and programmed to control the steering angles of the two propulsion devices so that the operating point of the resultant force is positioned on a right-left direction line extending perpendicularly to the central line along a right-left direction through the rotational center when the operating device outputs the lateral movement command. 
     
     
       3. The vessel propulsion system according to  claim 1 , wherein the controller is configured and programmed to control the steering angle of the first propulsion device that generates the backward thrust, so that the thrust of the first propulsion device follows a straight traveling direction; and
 the straight traveling direction is parallel or substantially parallel to the front-rear direction. 
 
     
     
       4. The vessel propulsion system according to  claim 1 , wherein the controller is configured and programmed to control the thrusts of the two propulsion devices so that, when the operating device outputs the lateral movement command, the thrust of the second propulsion device that generates the forward thrust is greater than the thrust of the first propulsion device that generates the backward thrust. 
     
     
       5. The vessel propulsion system according to  claim 1 , wherein the operating device is configured to output a diagonal movement command to cause a movement in a diagonal direction that obliquely intersects the central line; and
 the controller is configured and programmed to increase or decrease the thrust of the second propulsion device that generates the forward thrust so that the hull moves in a diagonal direction in response to receipt of a diagonal movement command generated by the operating device being moved diagonally after a lateral movement. 
 
     
     
       6. The vessel propulsion system according to  claim 5 , wherein, the controller is configured and programmed to increase the thrust of the second propulsion device that generates the forward thrust responsive to the diagonal movement command being a diagonally forward movement command, and the controller is configured and programmed to decrease the thrust of the second propulsion device that generates the forward thrust responsive to the diagonal movement command being a diagonally backward movement command. 
     
     
       7. The vessel propulsion system according to  claim 6 , wherein the controller is configured and programmed to control the steering angles of the two propulsion devices so that, responsive to the diagonal movement command being a diagonally forward movement command, the operating point of the resultant force is positioned ahead of the rotational center and so that, responsive to the diagonal movement command being a diagonally backward movement command, the operating point of the resultant force is positioned behind the rotational center. 
     
     
       8. The vessel propulsion system according to  claim 1 , wherein the controller is configured and programmed to control the steering angles and the thrusts of the two propulsion devices so that a half-line drawn so as to pass through the operating point of the resultant force from the rotational center coincides with a line of action of the resultant force. 
     
     
       9. The vessel propulsion system according to  claim 1 , wherein the operating device is configured to output a turning command to cause the hull to turn round; and
 when the operating device outputs the turning command along with the lateral movement command, the controller is configured and programmed to change the steering angle of the second propulsion device that generates the forward thrust to cause the hull to turn round. 
 
     
     
       10. The vessel propulsion system according to  claim 9 , wherein the controller is configured and programmed to control the steering angles of the two propulsion devices so that, when the operating device outputs the turning command along with the lateral movement command, the operating point of the resultant force is positioned to deviate in the front-rear direction of the vessel from the operating point of the resultant force during lateral movement. 
     
     
       11. A vessel comprising:
 a hull; 
 at least two propulsion devices that are disposed on a left side and on a right side, respectively, with respect to a central line extending in a front-rear direction through a rotational center of the hull, that are attached to the hull, and that are variable in thrust and in steering angle; 
 an operating device configured to output a lateral movement command to cause the hull to make a lateral movement in a lateral direction perpendicular to the central line, the lateral movement command including a commanded direction of either a rightward direction or a leftward direction in accordance with an operation performed by an operator; and 
 a controller configured and programmed to control the thrust and the steering angle of each of the two propulsion devices so that, when the operating device outputs a lateral movement command, a first one of the two propulsion devices that is disposed on a side existing in the commanded direction with respect to the central line generates a backward thrust, whereas a second one of the two propulsion devices that is disposed on a side existing in a direction opposite to the commanded direction with respect to the central line generates a forward thrust, and so that an operating point of a resultant force of the thrusts of the two propulsion devices is positioned to deviate to the side in the commanded direction from the central line, and so that a direction of action of the resultant force follows the commanded direction. 
 
     
     
       12. The vessel according to  claim 11 , wherein the controller is configured and programmed to control the steering angles of the two propulsion devices so that the operating point of the resultant force is positioned on a right-left direction line extending perpendicularly to the central line along a right-left direction through the rotational center when the operating device outputs a lateral movement command. 
     
     
       13. The vessel according to  claim 11 , wherein the controller is configured and programmed to control the steering angle of the first propulsion device that generates the backward thrust, so that the thrust of the first propulsion device follows a straight traveling direction; and
 the straight traveling direction is parallel or substantially parallel to the front-rear direction. 
 
     
     
       14. The vessel according to  claim 11 , wherein the controller is configured and programmed to control the thrusts of the two propulsion devices so that, when the operating device outputs a lateral movement command, the thrust of the second propulsion device that generates the forward thrust is greater than the thrust of the first propulsion device that generates the backward thrust. 
     
     
       15. The vessel according to  claim 11 , wherein the operating device is configured to output a diagonal movement command to cause a movement in a diagonal direction that obliquely intersects the central line; and
 the controller is configured and programmed to increase or decrease the thrust of the second propulsion device that generates the forward thrust so that the hull moves in a diagonal direction in response to receipt of a diagonal movement command generated by the operating device being moved diagonally after a lateral movement. 
 
     
     
       16. The vessel according to  claim 15 , wherein, the controller is configured and programmed to increase the thrust of the second propulsion device that generates the forward thrust in response to the diagonal movement command being a diagonally forward movement command, and the controller is configured and programmed to decrease the thrust of the second propulsion device that generates the forward thrust in response to the diagonal movement command being a diagonally backward movement command. 
     
     
       17. The vessel according to  claim 16 , wherein the controller is configured and programmed to control the steering angles of the two propulsion devices so that, in response to the diagonal movement command being a diagonally forward movement command, the operating point of the resultant force is positioned ahead of the rotational center and so that, in response to the diagonal movement command being a diagonally backward movement command, the operating point of the resultant force is positioned behind the rotational center. 
     
     
       18. The vessel according to  claim 11 , wherein the controller is configured and programmed to control the steering angles and the thrusts of the two propulsion devices so that a half-line drawn so as to pass through the operating point of the resultant force from the rotational center coincides with a line of action of the resultant force. 
     
     
       19. The vessel according to  claim 11 , wherein the operating device is configured to output a turning command to cause the hull to turn round; and
 when the operating device outputs the turning command along with the lateral movement command, controller is configured and programmed to change the steering angle of the second propulsion device that generates the forward thrust to cause the hull to turn round. 
 
     
     
       20. The vessel according to  claim 19 , wherein the controller is configured and programmed to control the steering angles of the two propulsion devices so that, when the operating device outputs the turning command along with the lateral movement command, the operating point of the resultant force is positioned to deviate in the front-rear direction of the vessel from the operating point of the resultant force during lateral movement.